This invention relates to a group of hydroxamic acid compounds and derivatives which inhibit matrix metalloproteinase enzymes and thus are useful for treating diseases resulting from tissue breakdown, such as heart disease, multiple sclerosis, arthritis, atherosclerosis, and osteoporosis.
Matrix metalloproteinases (sometimes referred to as MMPs) are naturally occurring enzymes found in most mammals. Over-expression and activation of MMPs or an imbalance between MMPs and inhibitors of MMPs have been suggested as factors in the pathogenesis of diseases characterized by the breakdown of extracellular matrix or connective tissues.
Stromelysin-1 and gelatinase A are members of the matrix metalloproteinases (MMP) family. Other members include fibroblast collagenase (MMP-1), neutrophil collagenase (MMP-8), gelatinase B (92 kDa gelatinase) (MMP-9), stromelysin-2 (MMP-10), stromelysin-3 (MMP-11), matrilysin (MMP-7), collagenase 3 (MMP-13), TNF-alpha converting enzyme (TACE), and other newly discovered membrane-associated matrix metalloproteinases (Sato H., Takino T., Okada Y., Cao J., Shinagawa A., Yamamoto E., and Seiki M., Nature, 1994;370:61-65). These enzymes have been implicated with a number of diseases which result from breakdown of connective tissue, including such diseases as rheumatoid arthritis, osteoarthritis, osteoporosis, periodontitis, multiple sclerosis, gingivitis, corneal epidermal and gastric ulceration, atherosclerosis, neointimal proliferation which leads to restenosis and ischemic heart failure, and tumor metastasis. A method for preventing and treating these and other diseases is now recognized to be by inhibiting metalloproteinase enzymes, thereby curtailing and/or eliminating the breakdown of connective tissues that results in the disease states.
The catalytic zinc in matrix metalloproteinases is typically the focal point for inhibitor design. The modification of substrates by introducing zinc chelating groups has generated potent inhibitors such as peptide hydroxamates and thiol-containing peptides. Peptide hydroxamates and the natural endogenous inhibitors of MMPs (TIMPs) have been used successfully to treat animal models of cancer and inflammation.
The ability of the matrix metalloproteinases to degrade various components of connective tissue makes them potential targets for controlling pathological processes. For example, the rupture of atherosclerotic plaques is the most common event initiating coronary thrombosis. Destabilization and degradation of the extracellular matrix surrounding these plaques by MMPs has been proposed as a cause of plaque fissuring. The shoulders and regions of foam cell accumulation in human atherosclerotic plaques show locally increased expression of gelatinase B, stromelysin-1, and interstitial collagenase. In situ zymography of this tissue revealed increased gelatinolytic and caseinolytic activity (Galla Z. S., Sukhova G. K., Lark M. W., and Libby P., xe2x80x9cIncreased expression of matrix metalloproteinases and matrix degrading activity in vulnerable regions of human atherosclerotic plaques,xe2x80x9d J. Clin. Invest., 1994;94:2494-2503). In addition, high levels of stromelysin RNA message have been found to be localized to individual cells in atherosclerotic plaques removed from heart transplant patients at the time of surgery (Henney A. M., Wakeley P. R., Davies M. J., Foster K., Hembry R., Murphy G., and Humphries S., xe2x80x9cLocalization of stromelysin gene expression in atherosclerotic plaques by in situ hybridization,xe2x80x9d Proc. Nat""l. Acad. Sci., 1991;88:8154-8158).
Inhibitors of matrix metalloproteinases will have utility in treating degenerative aortic disease associated with thinning of the medial aortic wall. Increased levels of the proteolytic activities of MMPs have been identified in patients with aortic aneurysms and aortic stenosis (Vine N. and Powell J. T., xe2x80x9cMetalloproteinases in degenerative aortic diseases,xe2x80x9d Clin. Sci., 1991;81:233-239).
Heart failure arises from a variety of diverse etiologies, but a common characteristic is cardiac dilation which has been identified as an independent risk factor for mortality (Lee T. H., Hamilton M. A., Stevenson L. W., Moriguchi J. D., Fonarow G. C., Child J. S., Laks H., and Walden J. A., xe2x80x9cImpact of left ventricular size on the survival in advanced heart failure,xe2x80x9d Am. J. Cardiol., 1993;72:672-676). This remodeling of the failing heart appears to involve the breakdown of extracellular matrix. Matrix metalloproteinases are increased in patients with both idiopathic and ischemic heart failure (Reddy H. K., Tyagi S. C., Tjaha i.e., Voelker D. J., Campbell S. E., and Weber K. T., xe2x80x9cActivated myocardial collagenase in idiopathic dilated cardiomyopathy,xe2x80x9d Clin. Res., 1993;41:660A; Tyagi S. C., Reddy H. K., Voelker D., Tjara i.e., and Weber K. T., xe2x80x9cMyocardial collagenase in failing human heart,xe2x80x9d Clin. Res., 1993;41:681 A). Animal models of heart failure have shown that the induction of gelatinase is important in cardiac dilation (Armstrong P. W., Moe G. W., Howard R. J., Grima E. A., and Cruz T. F., xe2x80x9cStructural remodeling in heart failure: gelatinase induction,xe2x80x9d Can. J. Cardiol., 1994;10:214-220), and cardiac dilation precedes profound deficits in cardiac function (Sabbah H. N., Kono T., Stein P. D., Mancini G. B., and Goldstein S., xe2x80x9cLeft ventricular shape changes during the course of evolving heart failure,xe2x80x9d Am. J. Physiol., 1992;263:H266-H270).
Congestive heart failure (CHF) is a significant health care problem which currently accounts for 7% of total health care expenditures in the USA. Approximately 400,000 new cases of heart failure are identified annually. The primary cause for development of heart failure is ischemic heart disease, and most new cases occur after myocardial infarction. The number of hospital discharges for heart failure has increased from 377,000 in 1979 to 875,000 in 1993, and the number of deaths during the same period has risen 82.5%. The average mortality rate eight years following initial diagnosis is 85% for men and 65% for women.
The development of CHF begins as an injurious process to the myocardium that reduces cardiac function (especially contractile or pump function) either in a specific region(s) or throughout its entire extent (i.e., globally). Heart failure is said to exist whenever the myocardial injury is of sufficient severity to reduce the heart""s capacity to pump an adequate output of blood to satisfy the body""s tissue requirements either at rest or during exercise. The disease state of heart failure is not a static situation, but instead progressively worsens until death occurs either suddenly (e.g., by cardiac arrhythmia or embolism to the brain or lung) or gradually from pump failure per se. The progressive decline in heart function in patients with CHF is characterized by progressive enlargement of the ventricular chambers (i.e., ventricular dilatation) and thinning and fibrosis of the ventricular muscle. The progressive ventricular enlargement and accompanying histologic changes in the ventricular muscle are termed xe2x80x9cremodeling,xe2x80x9d a process that involves changes in myocardiocyte structure as well as changes in the amount and composition of the surrounding interstitial connective tissue. An important constituent of the interstitial connective tissue is a matrix of fibrillar collagen, the xe2x80x9ctissue scaffoldingxe2x80x9d that contributes to the maintenance of proper ventricular geometry and structural alignment of adjoining cardiomyocytes. The interstitial collagen matrix is subject to increased dissolution and repair during xe2x80x9cremodelingxe2x80x9d that leads to ventricular enlargement and progressive heart failure. The deterioration of the collagen matrix is effected by increased activity of matrix metalloproteinases, the inhibition of which is a new treatment for heart failure and ventricular dilatation. Ventricular dilatation, the severity of which is measured by the end-diastolic and end-systolic volumes, is a prognostic marker of the probability of subsequent morbidity and mortality. The larger the ventricular chamber dimensions, the greater the likelihood of subsequent morbid events. Not only is pump function impaired by remodeling and ventricular dilation, but the enlarged chambers are prone to formation of clots, which can lead to stroke or embolism to other major organs (e.g., kidney, legs, intestinal tract).
Standard treatment for heart failure utilizes diuretics to decrease fluid retention, angiotensin converting enzyme inhibitors (ACE-Is) to reduce cardiac workload on the failing heart via vasodilation, and in the final stages of failure the positive inotrope digitalis to maintain cardiac output. Although ACE-Is have the benefit of increasing longevity unlike diuretics or positive inotropes, the beneficial effect of ACE-Is is limited to delaying death by only about 18 months. Clinical trials with xcex2-adrenergic blockers were recently conducted based on the hypothesis that reducing sympathetic drive would decrease the metabolic load on heart muscle cells. Unfortunately, this class of compounds was also found to not have a substantial effect on the progression of heart failure. The failure or limited success of previous heart failure therapies clearly shows that the controlling mechanism(s) mediating heart failure has not been targeted.
Drug development of the treatment of heart failure since the 1960s has focused on cardiac muscle cells. The goal has been to reduce the workload on the cells, improve blood flow to the cells, increase the contraction of the muscle, decrease the metabolic demand on cardiac myocytes, or some combination of these by various means. Focus on cardiac myocytes may have served to focus attention too far downstream. Overt heart failure may be caused by the breakdown of cardiac connective tissue. The breakdown in cardiac connective tissue proteins thus mediates cardiac dilation, one of the earliest characteristics of heart failure.
We have now discovered that compounds which inhibit MMPs that mediate the breakdown of connective tissues are useful for treating heart failure and associated ventricular dilatation.
Neointimal proliferation, leading to restenosis, frequently develops after coronary angioplasty. The migration of vascular smooth muscle cells (VSMCs) from the tunica media to the neointima is a key event in the development and progression of many vascular diseases and a highly predictable consequence of mechanical injury to the blood vessel (Bendeck M. P., Zempo N., Clowes A. W., Galardy R. E., and Reidy M., xe2x80x9cSmooth muscle cell migration and matrix metalloproteinase expression after arterial injury in the rat,xe2x80x9d Circulation Research, 1994;75:539-545). Northern blotting and zymographic analyses indicated that gelatinase A was the principal MMP expressed and excreted by these cells. Further, antisera capable of selectively neutralizing gelatinase A activity also inhibited VSMC migration across basement membrane barrier. After injury to the vessel, gelatinase A activity increased more than 20-fold as VSMCs underwent the transition from a quiescent state to a proliferating, motile phenotype (Pauly R. R., Passaniti A., Bilato C., Monticone R., Cheng L., Papadopoulos N., Gluzband Y. A., Smith L., Weinstein C., Lakatta E., and Crow M. T., xe2x80x9cMigration of cultured vascular smooth muscle cells through a basement membrane barrier requires type IV collagenase activity and is inhibited by cellular differentiation,xe2x80x9d Circulation Research, 1994;75:41-54).
Normal kidney function is dependent on the maintenance of tissues constructed from differentiated and highly specialized renal cells which are in a dynamic balance with their surrounding extracellular matrix (ECM) components (Davies M. et al., xe2x80x9cProteinases and glomerular matrix turnover,xe2x80x9d Kidney Int., 1992;41:671-678). Effective glomerular filtration requires that a semi-permeable glomerular basement membrane (GBM) composed of collagens, fibronectin, enactin, laminin and proteoglycans is maintained. A structural equilibrium is achieved by balancing the continued deposition of ECM proteins with their degradation by specific metalloproteinases (MMP). These proteins are first secreted as proenzymes and are subsequently activated in the extracellular space. These proteinases are in turn subject to counter balancing regulation of their activity by naturally occurring inhibitors referred to as TIMPs (tissue inhibitors of metalloproteinases).
Deficiency or defects in any component of the filtration barrier may have catastrophic consequences for longer term renal function. For example, in hereditary nephritis of Alport""s type, associated with mutations in genes encoding ECM proteins, defects in collagen assembly lead to progressive renal failure associated with splitting of the GBM and eventual glomerular and interstitial fibrosis. By contrast in inflammatory renal diseases such as glomerulonephritis, cellular proliferation of components of the glomerulus often precede obvious ultrastructural alteration of the ECM matrix. Cytokines and growth factors implicated in proliferative glomerulonephritis such as interleukin-1, tumor necrosis factor, and transforming growth factor beta can unregulate metalloproteinase expression in renal mesangial cells (Martin J. et al., xe2x80x9cEnhancement of glomerular mesangial cell neutral proteinase secretion by macrophages: role of interleukin 1,xe2x80x9d J. Immunol., 1986;137:525-529; Marti H. P. et al., xe2x80x9cHomology cloning of rat 72 kDa type IV collagenase: Cytokine and second-messenger inducibility in mesangial cells,xe2x80x9d Biochem. J., 1993;291:441-446; Marti H. P. et al., xe2x80x9cTransforming growth factor-b stimulates glomerular mesangial cell synthesis of the 72 kDa type IV collagenase,xe2x80x9d Am. J. Pathol., 1994;144:82-94). These metalloproteinases are believed to be intimately involved in the aberrant tissue remodeling and cell proliferation characteristic of renal diseases, such as, IgA nephropathy which can progress to through a process of gradual glomerular fibrosis and loss of functional GBM to end-stage renal disease. Metalloproteinase expression has already been well-characterized in experimental immune complex-mediated glomerulonephritis such as the anti-Thy 1.1 rat model (Bagchus W. M., Hoedemaeker P. J., Rozing J., Bakker W. W., xe2x80x9cGlomerulonephritis induced by monoclonal anti-Thy 1.1 antibodies: A sequential histological and ultrastructural study in the rat,xe2x80x9d Lab. Invest., 1986;55:680-687; Lovett D. H., Johnson R. J., Marti H. P., Martin J., Davies M., Couser W. G., xe2x80x9cStructural characterization of the mesangial cell type IV collagenase and enhanced expression in a model of immune complex mediated glomerulonephritis,xe2x80x9d Am. J. Pathol., 1992;141:85-98).
Unfortunately at present, there are very limited therapeutic strategies for modifying the course of progressive renal disease. Although many renal diseases have an inflammatory component, their responses to standard immunosuppressive regimes are unpredictable and potentially hazardous to individual patients. The secondary consequences of gradual nephron failure such as activation of the renin-angiotensin system, accompanied by individual nephron glomerular hyperfiltration and renal hypertension, may be effectively treated with ACE inhibitors or angiotensin II receptor antagonists; but at best, these compounds can only reduce the rate of GFR decline.
A novel strategy to treat at least some renal diseases has been suggested by recent observations of MMP behavior. A rat mesangial cell MMP has been cloned (MMP-2) which is regulated in a tissue specific manner, and in contrast to other cellular sources such as tumor cell lines, is induced by cytokines (Brown P. D., Levy A. T., Margulies I., Liotta L. A., Stetler-Stevenson W. G., xe2x80x9cIndependent expression and cellular processing of Mr 72,000 type IV collagenase and interstitial collagenase in human tumorigenic cell lines,xe2x80x9d Cancer Res., 1990;50:6184-6191; Marti H. P. et al., xe2x80x9cHomology cloning of rat 72 kDa type IV collagenase: Cytokine and second-messenger inducibility in mesangial cells,xe2x80x9d Biochem. J., 1993;291:441-446). While MMP-2 can specifically degrade surrounding ECM, it also affects the phenotype of adjacent mesangial cells. Inhibition of MMP-2 by antisense oligonucleotides or transfection techniques can induce a reversion of the proliferative phenotype of cultured mesangial cells to a quiescent or non-proliferative phenotype mimicking the natural in vitro behavior of these cells (Kitamura M. et al., xe2x80x9cGene transfer of metalloproteinase transin induces aberrant behaviour of cultured mesangial cells,xe2x80x9d Kidney Int., 1994;45:1580-1586; Turck J. et al., xe2x80x9cMatrix metalloproteinase 2 (gelatinase A) regulates glomerular mesangial cell proliferation and differentiation,xe2x80x9d J. Biol. Chem., 1996;271:15074-15083).
Collagenase and stromelysin activities have been demonstrated in fibroblasts isolated from inflamed gingiva (Uitto V. J., Applegren R., and Robinson P. J., xe2x80x9cCollagenase and neutral metalloproteinase activity in extracts from inflamed human gingiva,xe2x80x9d J. Periodontal Res., 1981;16:417-424), and enzyme levels have been correlated to the severity of gum disease (Overall C. M., Wiebkin O. W., and Thonard J. C., xe2x80x9cDemonstrations of tissue collagenase activity in vivo and its relationship to inflammation severity in human gingiva,xe2x80x9d J. Periodontal Res., 1987;22:81-88). Proteolytic degradation of extracellular matrix has been observed in corneal ulceration following alkali burns (Brown S. I., Weller C. A., and Wasserman H. E., xe2x80x9cCollagenolytic activity of alkali burned corneas,xe2x80x9d Arch. Opthalmol., 1969;81:370-373). Thiol-containing peptides inhibit the collagenase isolated from alkali-burned rabbit corneas (Burns F. R., Stack M. S., Gray R. D., and Paterson C. A., Invest. Opththamol., 1989;30:1569-1575).
Stromelysin is produced by basal keratinocytes in a variety of chronic ulcers (Saarialho-Kere U. K., Ulpu K., Pentland A. P., Birkedal-Hansen H., Parks W. C., Welgus H. G., xe2x80x9cDistinct populations of basal keratinocytes express stromelysin-1 and stromelysin-2 in chronic wounds,xe2x80x9d J. Clin. Invest., 1994;94:79-88).
Stromelysin-1 mRNA and protein were detected in basal keratinocytes adjacent to but distal from the wound edge in what probably represents the sites of proliferating epidermis. Stromelysin-1 may thus prevent the epidermis from healing.
Davies et al. (Cancer Res., 1993;53:2087-2091) reported that a peptide hyroxamate, BB-94, decreased the tumor burden and prolonged the survival of mice bearing human ovarian carcinoma xenografts. A peptide of the conserved MMP propeptide sequence was a weak inhibitor of gelatinase A and inhibited human tumor cell invasion through a layer of reconstituted basement membrane (Melchiori A., Albili A., Ray J. M., and Stetler-Stevenson W. G., Cancer Res., 1992;52:2353-2356), and the natural tissue inhibitor of metalloproteinase-2 (TIMP-2) also showed blockage of tumor cell invasion in in vitro models (DeClerck Y. A., Perez N., Shimada H., Boone T. C., Langley K. E., and Taylor S. M., Cancer Res., 1992;52:701-708). Studies of human cancers have shown that gelatinase A is activated on the invasive tumor cell surface (Strongin A. Y., Marmer B. L., Grant G. A., and Goldberg G. I., J. Biol Chem., 1993;268:14033-14039) and is retained there through interaction with a receptor-like molecule (Monsky W. L., Kelly T., Lin C. Y., Yeh Y., Stetler-Stevenson W. G., Mueller S. C., and Chen W. T., Cancer Res., 1993;53:3159-3164).
Inhibitors of MMPs have shown activity in models of tumor angiogenesis (Taraboletti G., Garofalo A., Belotti D., Drudis T., Borsotti P., Scanziani E., Brown P. D., and Giavazzi R., Journal of the National Cancer Institute, 1995;87:293; and Benelli R., Adatia R., Ensoli B., Stetler-Stevenson W. G., Santi L., and Albini A., Oncology Research, 1994;6:251-257).
Several investigators have demonstrated consistent elevation of stromelysin and collagenase in synovial fluids from rheumatoid and osteoarthritis patients as compared to controls (Walakovits L. A., Moore V. L., Bhardwaj N., Gallick G. S., and Lark M. W., xe2x80x9cDetection of stromelysin and collagenase in synovial fluid from patients with rheumatoid arthritis and post-traumatic knee injury,xe2x80x9d Arthritis Rheum., 1992;35:35-42; Zafarullal M., Pelletier J. P., Cloutier J. M., and Marcel-Pelletier J., xe2x80x9cElevated metalloproteinases and tissue inhibitor of metalloproteinase mRNA in human osteoarthritic synovia,xe2x80x9d J. Rheumatol., 1993;20:693-697). TIMP-1 and TIMP-2 prevented the formation of collagen fragments, but not proteoglycan fragments, from the degradation of both the bovine nasal and pig articular cartilage models for arthritis, while a synthetic peptide hydroxamate could prevent the formation of both fragments (Andrews H. J., Plumpton T. A., Harper G. P., and Cawston T. E., Agents Actions, 1992;37:147-154; Ellis A. J., Curry V. A., Powell E. K., and Cawston T. E., Biochem. Biophys. Res. Commun., 1994;201:94-101).
Gijbels et al. (J. Clin. Invest., 1994;94:2177-2182) recently described a peptide hydroxamate, GM6001, that suppressed the development or reversed the clinical expression of experimental allergic encephalomyelitis (EAE) in a dose dependent manner, suggesting the use of MMP inhibitors in the treatment of autoimmune inflammatory disorders such as multiple sclerosis.
A recent study by Madri has elucidated the role of gelatinase A in the extravasation of T-cells from the blood stream during inflammation (Ramanic A. M. and Madri J. A., xe2x80x9cThe Induction of 72-kD Gelatinase in T-Cells upon Adhesion to Endothelial Cells is VCAM-1 Dependent,xe2x80x9d J. Cell Biology, 1994;125:1165-1178). This transmigration past the endothelial cell layer is coordinated with the induction of gelatinase A and is mediated by binding to the vascular cell adhesion molecule-1 (VCAM-1). Once the barrier is compromised, edema and inflammation are produced in the CNS. Leukocytic migration across the blood-brain barrier is known to be associated with the inflammatory response in EAE. Inhibition of the metalloproteinase gelatinase A would block the degradation of extracellular matrix by activated T-cells that is necessary for CNS penetration.
These studies provided the basis for the belief that an inhibitor of stromelysin-1 and/or gelatinase A will treat diseases involving disruption of extracellular matrix resulting in inflammation due to lymphocytic infiltration, inappropriate migration of metastatic or activated cells, or loss of structural integrity necessary for organ function.
The need continues for low molecular weight molecules which can be economically prepared and yet are effective inhibitors of metalloproteinases. An object of the present invention is to provide such compounds, their pharmaceutical formulations, and a method for using them to treat diseases mediated by metalloproteinases.
The present invention provides matrix metalloproteinase inhibitors useful in treatment of diseases and conditions where inhibition of matrix metalloproteinase enzymes is considered beneficial.
The compounds of the invention are hydroxamic acid compounds having Formula I: 
or a pharmaceutically acceptable salt thereof, wherein X is selected from OH and NHOH, and d is 1 or 2.
R1 is selected from the group consisting of: 
wherein Y is selected from the group consisting of O, S, S(O)d (where d is 1 or 2), CH2, C(xe2x95x90O), and NRq (where Rq is H, C1-6 alkyl, or C1-6 alkyl phenyl); each Yxe2x80x2 is independently selected from the group consisting of O, S, SO2, CH2, C(xe2x95x90O), and NH; M is selected from the group consisting of O, S, and CH2; R5 is selected from the group consisting of H, C1-10 alkyl, CF3, CONH2, halo, CN, COOH, C1-4 alkoxy, CHO, NO2, OH, (CH2)pOH, (CH2)pNH2, Ar, and NH2; p is from 0 to 3; and Ar is selected from the group consisting of (a) phenyl; (b) phenyl substituted with C1-4 alkyl, C1-4 alkoxy, halo, NH2, NO2, CN, COOH, CONH2, CF3, or COOR6 (where R6 is C1-10 alkyl); and (c) heteroaryl.
R2 is selected from the group consisting of (a) hydrogen; (b) C1-4 alkyl; (c) benzyl; and (d) benzyl substituted with one or more of C1-4 alkyl, C1-4 alkoxy, F, Cl, Br, I, NH2, NO2, CN, carboxy, and CO2R7 (where R7 is H or C1-4 alkyl).
R3 and R4 are, independently, selected from the group consisting of C1-20 alkyl (straight chain or branched); C3-10 cycloalkyl; phenyl; phenyl substituted with C1-4 alkyl, C1-4 alkoxy, halo, NH2, NO2, CN, COOH, CO2R7 (wherein R7 is as defined above), or CF3; C3-10 heterocyclic; and heteroaryl. R3 and R4 can be taken together to form a ring structure (incorporating the alpha carbon atom adjacent the carbonyl group in Formula I), as xe2x80x94(CH2)sxe2x80x94 bonded to the carbon atom adjacent the carbonyl group in Formula I, where s is an integer from 2 to 10. The ring optionally can further include one or more heteroatoms.
A further embodiment of the invention is a pharmaceutical formulation comprising a compound of Formula I admixed with a diluent, carrier, or excipient therefor.
The invention also provides methods for inhibiting the action of a matrix metalloproteinase enzyme in a mammal comprising administering a matrix metalloproteinase inhibiting amount of a compound of Formula I.
The present invention is directed to compounds having Formula I: 
or a pharmaceutically acceptable salt thereof, wherein X is selected from OH and NHOH, and d is 1 or 2.
R1 is selected from the group consisting of: 
wherein Y and Yxe2x80x2 are independently selected from the group consisting of O, S, S(O)d (where d is 1 or 2), CH2, C(xe2x95x90O), and NRq (where Rq is H, C1-6 alkyl, or C1-6 alkyl phenyl); each Yxe2x80x2 is independently selected from the group consisting of O, S, SO2, CH2, C(xe2x95x90O), and NH; M is selected from the group consisting of O, S, and CH2; R5 is selected from the group consisting of H, C1-10 alkyl, CF3, CONH2, halo, CN, COOH, C1-4 alkoxy, CHO, NO2, OH, (CH2)pOH, (CH2)pNH2, Ar, and NH2; p is from 0 to 3; and Ar is selected from the group consisting of (a) phenyl; (b) phenyl substituted with C1-4 alkyl, C1-4 alkoxy, halo, NH2, NO2, CN, COOH, CONH2, CF3, or COOR6 (where R6 is C1-10 alkyl); and (c) heteroaryl, including, but not limited to, 2-, 3-, or 4-pyridyl, 2-, 4-, or 5- pyrimidinyl, 3- or 4-pyridazinyl, 2-pyrazinyl, 2- or 3-thienyl, 2- or 3-furanyl, 1-, 2-, 4-, or 5-imidazolyl, 1-, 3-, 4-, or 5-pyrazolyl, 1-, 2-, or 3-pyrrolyl, 2-, 4-, or 5-oxazolyl, 2-, 4-, or 5-thiazolyl, 3-, 4-, or 5-isoxazolyl, 2-, 3-, 4-, 5-, 6-, 7-, or 8-quinolinyl, or 3-, 4-, or 5-isothiazolyl.
Examples of R1 groups include the following: 
R2 is selected from the group consisting of (a) hydrogen; (b) C1-4 alkyl; (c) benzyl; and (d) benzyl substituted with one or more of C1-4 alkyl, C1-4 alkoxy, F, Cl, Br, I, NH2, NO2, CN, carboxy, and CO2R7 (where R7 is H or C1-4 alkyl).
R3 and R4 are, independently, selected from the group consisting of C1-20 alkyl (straight chain or branched); C3-10 cycloalkyl; phenyl; phenyl substituted with C1-4 alkyl, C1-4 alkoxy, halo, NH2, NO2, CN, COOH, CO2R7 (wherein R7 is as defined above), or CF3; C3-10 heterocyclic; and heteroaryl. Also, R3 and R4 can be bonded or taken together to form a spiro cyclic ring (incorporating the alpha carbon atom adjacent the carbonyl group in Formula I), as xe2x80x94(CH2)sxe2x80x94 bonded to the carbon atom adjacent the carbonyl group in Formula I, where s is an integer from 2 to 10 (more preferably 3 to 9). The ring systems optionally can further include one or more heteroatoms.
For example, R3 and R4 can be taken together as xe2x80x94(CH2)sxe2x80x94 where s is from 2 to 10, to form a C3-11 monocyclic ring, such as the following groups (wherein the terminal carbons are bonded to the alpha carbon atom adjacent the carbonyl group in Formula I): xe2x80x94CH2CH2xe2x80x94, xe2x80x94CH2CH2CH2xe2x80x94, xe2x80x94CH2CH2CH2CH2xe2x80x94, xe2x80x94CH2CH2CH2CH2CH2xe2x80x94, and xe2x80x94CH2CH2CH2CH2CH2CH2xe2x80x94 (forming 3-, 4-, 5-, 6-, and 7-membered rings, respectively).
R3 and R4 can be taken together to form one of the above-described spiro cyclic rings that additionally includes one or more heteroatoms (preferably 1 to 6 heteroatoms) at any location in the rings. The heteroatom is selected from the group consisting of O, S, and NR8 (where R8 is selected from H and C1-3 alkyl).
Thus, R3 and R4 can also be taken together to form the empirical formula xe2x80x94(CH2)sZgxe2x80x94, wherein terminal carbons are bonded to the alpha carbon atom, s is an integer from 2 to 10, and g is an integer from 0 to 3. Each Z is a heteroatom located at any position of the group taken as R3 and R4, and each Z is independently selected from the group consisting of O, S, and NR8 (where R8 is selected from H and C1-3 alkyl).
For example, a hetero-spiro cyclic ring may incorporate xe2x80x94(CH2)aZ(CH2)bxe2x80x94, where Z is the heteroatom (selected from the group consisting of O, S, and NR8), a is from 1 to 10, and b is from 1 to 10, and the total of a and b is not more than 11, such as the following (where the terminal carbons are both bonded to the alpha carbon atom adjacent the carbonyl group in Formula I): xe2x80x94CH2OCH2CH2xe2x80x94, xe2x80x94CH2CH2OCH2CH2xe2x80x94, xe2x80x94CH2CH2OCH2CH2CH2xe2x80x94, xe2x80x94CH2N(H)CH2CH2xe2x80x94, xe2x80x94CH2CH2N(H)CH2CH2xe2x80x94, xe2x80x94CH2CH2N(H)CH2CH2CH2xe2x80x94, xe2x80x94CH2SCH2CH2xe2x80x94, xe2x80x94CH2CH2SCH2CH2xe2x80x94, xe2x80x94CH2CH2SCH2CH2CH2xe2x80x94, xe2x80x94CH2OCH2CH2OCH2xe2x80x94, xe2x80x94CH2N(H)CH2CH2N(H)CH2xe2x80x94, and xe2x80x94CH2SCH2CH2SCH2xe2x80x94. Thus, exemplary compounds of the invention can be represented by the following formula (where Z is the heteroatom and h is 0 or 1). 
In preferred embodiments of compounds of Formula I, R1 groups are selected from the following: 
Preferably, d equals 2, R2 is hydrogen, and X is NHOH or OH. R3 and R4 are preferably taken together to form a ringed structure, preferably selected from: xe2x80x94CH2CH2CH2CH2xe2x80x94 (where the terminal carbon atoms are bonded to the alpha carbon adjacent the carbonyl group in Formula I to form a cyclopentyl group); xe2x80x94CH2CH2CH2CH2CH2xe2x80x94 (where the terminal carbon atoms are bonded to the alpha carbon adjacent the carbonyl group in Formula I to form a cyclohexyl group); and xe2x80x94CH2CH2OCH2CH2xe2x80x94 (where the terminal carbon atoms are bonded to the alpha carbon adjacent the carbonyl group in Formula I to form a 6-membered heterocyclic). In other preferred embodiments, R3 and R4 are each a methyl group.
In the formulas defining the compounds of the invention, halo refers to fluoro, chloro, bromo, and iodo, with chloro and bromo being preferred.
The term xe2x80x9cC1-4 alkylxe2x80x9d or xe2x80x9calkyl C1-4xe2x80x9d means straight and branched aliphatic groups having from 1 to 4 carbon atoms, examples of which include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl. Thus, the term xe2x80x9cC1-20 alkylxe2x80x9d means straight and branched aliphatic groups having from 1 to 20 carbon atoms, and the term xe2x80x9cC1-10 alkylxe2x80x9d refers to straight and branched aliphatic groups having from 1 to 10 carbon atoms.
The term xe2x80x9calkoxyxe2x80x9d means an alkyl group attached to an oxygen atom. Representative examples of alkoxy groups include methoxy, ethoxy, tert-butoxy, propoxy, and isobutoxy.
The term xe2x80x9carylxe2x80x9d means an aromatic hydrocarbon group. Representative examples of aryl groups include phenyl and naphthyl.
The term xe2x80x9ccycloalkylxe2x80x9d means a cyclic aliphatic group. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl.
The symbol xe2x80x9cxe2x80x94xe2x80x9d means a bond.
The symbol: 
refers to a bonded R group.
A xe2x80x9cheteroatomxe2x80x9d is a nitrogen, oxygen, or sulfur atom.
The term xe2x80x9cheteroarylxe2x80x9d means a mono- or bi-cyclic ring system containing 1 or 2 aromatic rings and containing at least 1 nitrogen, oxygen, or sulfur atom in an aromatic ring. Examples of heteroaryl groups include, but are not limited to, 2- or 3-thienyl, 2- or 3-furanyl, 2- or 3-pyrrolyl, 2-, 3-, or 4-pyridinyl, 2-pyrazinyl, 2-, 4-, or 5-pyrimidinyl, 3- or 4-pyridazinyl, 1-, 2-, 4-, or 5-imidazolyl, 1-, 3-, 4-, or 5-pyrazolyl, 2-, 4-, or 5-oxazolyl, 2-, 4-, or 5-thiazolyl, 3-, 4-, or 5-isoxazolyl, 3-, 4-, or 5-isothiazolyl, or 2-, 3-, 4-, 5-, 6-, or 7-indolyl. A heteroaryl can be substituted or unsubstituted, for example, with one or more, and in particular 1 to 3, substituents, such as halo, alkyl, hydroxy, hydroxyalkyl, alkoxy, alkoxyalkyl, haloalkyl, nitro, amino, alkylamino, acylamino, alkylthio, alkylsulfinyl, and alkylsulfonyl.
Thus, the MMP inhibiting compounds of the invention are derived from xcex1, xcex1xe2x80x2-disubstituted amino acids. The compounds where X equals NHOH are also referred to as hydroxamic acid compounds. The use of the zinc-binding hydroxamic acid moiety preferably provides compounds that inhibit all identified MMPs with superior (e.g., nanomolar range) potency over the corresponding carboxylic acids.
The compounds of the present invention can be therapeutically administered as the neat chemical, but it is preferable to administer compounds of Formula I as a pharmaceutical composition or formulation, as described below in further detail. Accordingly, the present invention further provides for pharmaceutical formulations comprising a compound of Formula I, together with one or more pharmaceutically acceptable carriers, and, optionally, other therapeutic and/or prophylactic ingredients. The carriers and other additives are xe2x80x9cacceptablexe2x80x9d in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.
The term xe2x80x9cpharmaceutically acceptable salts and prodrugsxe2x80x9d refers to those salts (including carboxylate salts and amino acid addition salts) and prodrugs (including esters and amides) of the compounds of the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of patients without undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the invention.
The term xe2x80x9csaltsxe2x80x9d refers to the relatively non-toxic, inorganic and organic acid addition salts of compounds of the present invention. These salts can be prepared in situ during the final isolation and purification of the compounds or by separately reacting the purified compound in its free base form with a suitable organic or inorganic acid and isolating the salt thus formed. Representative anions include bromide, chloride, sulfate, bisulfate, nitrate, acetate, oxalate, valerate, oleate, palmitate, stearate, laurate, borate, benzoate, lactate, phosphate, tosylate, citrate, maleate, fumarate, succinate, tartrate, naphthylate, mesylate, glucoheptonate, lactiobionate and laurylsulfonate, and the like. Cations include the alkali and alkaline earth metals, such as sodium, lithium, potassium, calcium, magnesium and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like. See, for example, Berge S. M. et al., xe2x80x9cPharmaceutical Salts,xe2x80x9d J. Pharm. Sci., 1977;66:1-19, the disclosure of which is hereby incorporated herein by reference.
The term xe2x80x9cprodrugxe2x80x9d refers to compounds that are transformed in vitro, preferably rapidly, to yield the parent compound of the above formulae, for example, by hydrolysis in blood or other location. A thorough discussion is provided in T. Higuchi and V. Stella, xe2x80x9cPro-drugs as Novel Delivery Systems,xe2x80x9d Vol. 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987, the disclosures of both of which are hereby incorporated herein by reference.
Esters and amides can be used as prodrugs for the biologically active carboxylic acids of the present invention. Examples of pharmaceutically acceptable, non-toxic esters of the compounds of this invention include C1-C6 alkyl esters wherein the alkyl group is a straight or branched chain. Acceptable esters also include C5-C7 cycloalkyl esters as well as arylalkyl esters such as, but not limited to, benzyl. C1-C4 alkyl esters are preferred. Esters of the compounds of the present invention may be prepared according to conventional methods.
Examples of pharmaceutically acceptable, non-toxic amides of the compounds of this invention include amides derived from ammonia, primary C1-C6 alkyl amines and secondary C1-C6 dialkyl amines wherein the alkyl groups are straight or branched chain. In the case of secondary amines, the amine may also be in the form of a 5- or 6-membered heterocycle containing one nitrogen atom. Amides derived from ammonia, C1-C3 alkyl primary amines and C1-C2 dialkyl secondary amines are preferred. Amides of the compounds of the invention may be prepared according to conventional methods.
In addition, the compounds of the present invention can exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like. In general, the solvated forms are considered equivalent to the unsolvated forms for the purposes of the present invention.
As appreciated by persons skilled in the art, reference herein to treatment extends to prophylaxis, as well as treatment of established diseases or symptoms. It is further appreciated that the amount of a compound of the invention required for use in treatment varies with the nature of the condition being treated, and with the age and condition of the patient and is ultimately determined by the attendant physician or veterinarian.
The pharmaceutical preparation is preferably in unit dosage form. The desired dose can be conveniently administered in a single dose, or as multiple doses administered at appropriate intervals, for example, as two, three, four, or more subdoses per day. In such form the preparation is subdivided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation, the package containing discrete quantities of preparation, such as packeted tablets, capsules, and powders in vials or ampoules. Also the unit dosage form can be a capsule, tablet, cachet, or lozenge itself, or it can be the appropriate number of any of these in packaged form.
In therapeutic use as agents to inhibit a matrix metalloproteinase enzyme for the treatment of the conditions and diseases described herein, the compounds utilized in the pharmaceutical method of this invention are administered at a dose that is effective to inhibit the hydrolytic activity of one or more matrix metalloproteinase enzymes. The quantity of active component in a unit dose preparation may be varied or adjusted from about 0.1 to about 1000 mg, preferably about 10 to about 100 mg, according to the particular application and the potency of the active component.
An initial dosage of about 0.1 to about 500 mg per kilogram of body weight daily, for example about 1 to about 100 mg per kilogram of body weight daily, will generally be effective. A daily dose range of about 25 to about 75 mg per kilogram of body weight may be desirable. The dosages, however, may be varied depending upon the requirements of the patient, the severity of the condition being treated, and the compound being employed. Determination of the proper dosage for a particular situation is within the skill of the art. The composition can, if desired, also contain other compatible therapeutic agents.
Generally, treatment is initiated with smaller dosages which are less than the optimum dose of the compound. Thereafter, the dosage may be increased by small increments until the optimum effect under the circumstance is reached. For convenience, the total daily dosage may be divided and administered in portions during the day if desired. Typical dosages will be from about 0.1 to about 1000 mg per day, and more preferably about 25 to about 250 mg per day, such that an amount is provided that is effective to treat the particular disease being prevented or controlled. For a normal human adult having a body weight of about 70 kg, a dosage in the range of about 0.01 to about 100 mg per kilogram of body weight per day is preferable. The specific dosage used, however, can vary. For example, the dosage can depend on a number of factors including the requirements of the patient, the severity of the condition being treated, and the pharmacological activity of the compound being used. The determination of optimum dosages for a particular patient is well-known to those skilled in the art. The term xe2x80x9cpatientxe2x80x9d includes humans and animals.
The compounds and formulations of the present invention can be prepared and administered in a wide variety of oral and parenteral dosage forms. Thus, the compounds of the present invention can be administered by injection, that is intravenously, intramuscularly, intracutaneously, subcutaneously, intraduodenally, intra-arterially, intramuscularly, intra-articularly, and intraperitoneally, for example. Also, the compounds of the present invention can be administered by inhalation, for example, intranasally or deep lung inhalation. Additionally, the compounds of the present invention can be administered transdermally. The compounds of the invention can be administered transmucosally (e.g., sublingually or via buccal administration) or rectally. Ophthalmic formulations, eye ointments, powders, and solutions are also contemplated as being within the scope of this invention. Formulations of the invention are also described below in detail.
Those of skill in the art will understand that the following dosage forms may comprise as the active component, either a compound of the Formula I (including the preferred embodiments disclosed herein) or a corresponding pharmaceutically acceptable salt of a compound of Formula I.
The synthesis of exemplary sulfonamides of Formula I can be accomplished by the following preferred general schemes. Unless otherwise noted, all starting materials were obtained from commercial suppliers and used without further purification.
A mixture of sodium phenoxide and a cycloalkeneoxide (where n is preferably 1 to 3) as shown below, are refluxed in water to form the hydroxy-ether compound of Formula II. The hydroxy-ether compound is oxidized to a ketone of Formula III using Jones Reagent or any other suitable oxidant. 
The ketone (III) is added to a mixture of sulfuric acid and phosphoric acid at 0xc2x0 C. and allowed to warm to room temperature to form the compound of Formula IV. 
The compound of Formula IV is refluxed in an inert solvent such as 1,2-dichloroethane or dichloromethane with sulfur trioxide in dimethylformamide (SO3.DMF) to form a sulfonic acid sodium salt of Formula V. 
A sulfonyl chloride can be formed by refluxing the sodium salt of Formula V with an appropriate chlorinating agent such as thionyl chloride (SOCl2), either neat or in an inert solvent such as toluene (C6H5CH3) to produce the sulfonyl chloride of Formula VI. 
The sulfonyl chloride of Formula VI and a selected amino acid ester are coupled in an appropriate solvent such as aqueous tetraydrofuran or anhydrous tetrahydrofuran (xe2x80x9cTHFxe2x80x9d) with an acid scavenger such as triethylamine (xe2x80x9c(NEt3)xe2x80x9d) , for example to produce the methyl ester of Formula VII. 
From the methyl ester of Formula VII, a carboxylic acid of Formula VIII can be formed through base hydrolysis in aqueous tetrahydrofuran. The hydroxamic acid of Formula IX can be formed by first stirring the carboxylic acid with oxalyl chloride ((COCl)2) or another suitable chlorinating agent in an inert solvent such as 1,2-dichloroethane or dichloromethane, to generate a carboxylic acid chloride which is then reacted with a solution of hydroxylamine to give the desired hydroxamic acid of Formula IX. The compounds of Formulas VIII and IX are preferred compounds of the invention, e.g., of Formula I. 
Another preferred scheme for producing preferred compounds of the invention is described below. A compound of the Formula X can be made by reduction of the sulfonic acid sodium salt of the Formula V (where n is preferably 1 to 3) from Scheme 1 in a solvent such as ethanol (EtOH) and aqueous tetrahydrofuran with palladium (20% Pd/C) or other suitable metal catalysts under hydrogen gas at elevated pressure. The sulfonyl chloride of the Formula XI can then be produced from the compound of Formula X by refluxing with an appropriate chlorinating agent such as phosphorus trichloride (PCl3). 
The sulfonyl chloride of Formula XI is then combined with a selected amino acid ester in a solvent such as aqueous tetrahydrofuran or anhydrous tetrahydrofuran with an appropriate acid scavenger such as triethylamine (NEt3) to form an N-sulfonamide amino acid ester, for example, the ester of Formula XII. 
Base hydrolysis of the ester of Formula XII forms the carboxylic acid of Formula XIII. A hydroxamic acid, for example the acid of Formula XIV, can then be formed by first stirring the carboxylic acid of Formula XIII with oxalyl chloride or other suitable chlorinating agent in an inert solvent such as 1,2-dichloroethane or dichloromethane, and then reacting the resultant carboxylic acid chloride with hydroxylamine. 
Preferred compounds of the invention can generally be prepared according to the synthetic schemes described herein. In each scheme, it is understood in the art that protecting groups can be employed where necessary in accordance with general principals of synthetic chemistry. Such protecting groups can be removed in the final steps of the synthesis under basic, acidic, or hydrogenolytic conditions which are readily apparent to those skilled in the art. By employing appropriate manipulation and protection of any chemical functionalities, synthesis of compounds of the invention not specifically set forth herein can be accomplished by methods analogous to the schemes set forth herein.
The present invention includes all possible stereoisomers and geometric isomers of compounds of Formula I, and includes not only racemic compounds but also the optically active isomers as well, for example where the substituents R3 and R4 differ. When a compound of Formula I is desired as a single enantiomer, it can be obtained either by resolution of the final product or by stereospecific synthesis from either isomerically pure starting material or any conventional intermediate. Resolution of the final product, an intermediate, or a starting material can be achieved by any suitable method known in the art. Additionally, in situations where tautomers of the compounds in Formula I are possible, the present invention is intended to include all tautomeric forms of the compounds.
The synthesis of typical sulfonamides of Formula I is illustrated by the following examples. The examples are representative only, and are not intended to be limiting in any respect. The ratios disclosed herein are volume ratios unless otherwise noted.